In addition to the above characteristics of a ‘good guest post’ and to make sure that you will benefit from the advantages and not suffer from the disadvantages, you need to set very strict criteria before accepting any guest post.
Allow guest posting only from people who have a verified Google+ profile
Don’t allow text links within the body of the article
Don’t allow keyword stuffed links in the author bio
Allow for only one link in the author bio
Guest posts should be over 1500 words.
Allow guest posts from authors who have strong social media profiles (at least on Google+, Facebook and Twitter)
Finally its your personal choice and individual decision.